Ligament fixation system, implants, and devices with a compression cap, and methods of use

ABSTRACT

Implants, devices, systems, and methods for achieving ligament fixation are disclosed. An implant comprises a cap member comprising an internally threaded opening extending from a first end thereof, an anchor portion comprising a first end that defines a tip of the implant and external threads, and a coupling portion extending between the cap member and the anchor portion. The coupling portion of the implant includes an externally threaded portion threadably coupled within the internally threaded opening of the cap member. The cap member of the implant is longitudinally moveable along the coupling portion. Insertion instruments for inserting an implant for ligament fixation are also disclosed. Methods of using an implant for achieving ligament fixation are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of PCT international patentapplication No. PCT/US2018/057554, filed Oct. 25, 2018, entitledLigament Fixation System, Implants, and Devices with a Compression Cap,and Methods of Use, which claims the benefit of U.S. provisionalapplication No. 62/576,946, filed Oct. 25, 2017, entitled LigamentFixation System, Implants, and Devices with a Compression Cap, andMethods of Use, which are hereby incorporated herein by reference intheir entireties.

TECHNICAL FIELD

The present invention relates generally to general, podiatric, andorthopaedic surgery related to fixation of ligaments. More specifically,but not exclusively, the present invention relates to ligament fixationimplants, devices, and systems with compression caps, as well asinsertion instruments and methods for achieving ligament fixation.

BACKGROUND OF THE INVENTION

Syndesmotic injuries are a result of trauma (not specific to sportsinjuries) and can occur as a purely ligamentous injury or in combinationwith an ankle fracture. These ligaments become disrupted, separated, orinjured where semi-constrained approximation and fixation is needed toaide in healing without the need for a second surgery, such as removalof a rigid fixation screw. The current standard of care for syndesmoticinjuries involves either rigid fixation with a screw, or a tether-basedconstraint across the entire width of the ankle (TightRope, etc.).

The more rigid screw-based fixation is simple to implant and stabilizesthe joint, but fails to allow any motion at all, as would normally existphysiologically. This limits the patient's range of motion, andunpredictable screw failure locations can result in damage to existingbone and patient pain.

Tethered constraints, such as the Arthrex Tightrope, do allow for motionof the joint, but by spanning the entire width of the ankle, fail tomimic the intact ligament structures of the syndesmosis in terms ofattachment location and distance between the tibia and fibula. However,tethered constraints result in a necessary decrease in structuralstrength due to the associated surgical technique of, for example, theTightrope, and for these devices which involve drilling a hole throughboth the tibia and fibula which remains unfilled by structural material(e.g. a metal screw).

Thus, new and improved devices, systems, and methods for achievingligament fixation are needed to overcome the above-noted drawbacks ofthe currently available solutions for addressing syndesmotic injuries.

SUMMARY OF THE INVENTION

The present disclosure is directed toward devices and methods for use inligament fixation. The devices, systems, and methods for achievingligament fixation.

In one aspect of the present disclosure provided herein, is an implant.The implant including an end member, an anchor member coupled to the endmember, and a cap member removably coupled to the end member.

In another aspect of the present disclosure provided herein, is a methodfor inserting an implant. The method includes obtaining the implant. Theimplant includes an end member, an anchor member coupled to the endmember, and a cap member removably coupled to the end member. The methodalso includes engaging the end member with an insertion instrument andinserting the coupled end member and anchor member into a patient toposition the end member in a first bone and the anchor member in asecond bone. The method further includes inserting the cap member overthe end member to compress the first bone and the second bone.

In yet another aspect of the present disclosure provided herein, is asystem. The system including an implant and an insertion instrument forcoupling to the implant. The implant including an end member, an anchormember coupled to the end member, and a cap member removably coupled tothe end member.

In another aspect of the present disclosure, an implant is provided. Theimplant comprises a cap member comprising an internally threaded openingextending from a first end thereof, an anchor portion comprising a firstend that defines a tip of the implant and external threads, and acoupling portion extending between the cap member and the anchorportion. The coupling portion includes an externally threaded portionthreadably coupled within the internally threaded opening of the capmember. The cap member is longitudinally moveable along the couplingportion.

In some embodiments, the coupling portion comprises a breakaway portion.In some such embodiments, the breakaway portion is comprised of acircumferential groove. In some embodiments, the coupling portion is ofone-piece construction. In some embodiments, the cap member, the anchorportion and the coupling portion are integral. In some embodiments, thecoupling portion comprises a torque application feature comprising outerplanar surfaces circumferentially arranged about the coupling portion.In some embodiments, the cap member comprises a shaft portion thatdefines the first end of the cap member and includes the internallythreaded opening, and an enlarged head portion extending from the shaftportion that defines a second end of the cap member, the second end ofthe cap member defining a free end of the implant that opposes the tipof the implant.

In some embodiments, the cap member further comprises a non-circulardrive opening extending from the second end thereof. In someembodiments, the anchor portion comprises a shaft portion with a firstend and a second end, a proximal coupling portion extending from thefirst end of the shaft portion of the anchor member to the couplingportion, and a distal portion extending from the second end of the shaftportion of the anchor member. In some such embodiments, at least aportion of the shaft portion of the anchor member comprises the externalthreads. In some such embodiments, the proximal coupling portion is voidof external threads.

In some embodiments, the distal portion comprises at least one surfacefeature positioned proximate to the first end of the anchor member. Insome such embodiments, the at least one surface feature comprises atleast one cutting flute. In some embodiments, the at least one surfacefeature comprises a plurality of circumferentially arrangedlongitudinally extending flutes.

In some embodiments, the coupling portion comprises a coupling membercoupled to the anchor portion and an end member coupled to the couplingmember. In some such embodiments, the coupling member and the end memberare separate and distinct components. In some embodiments, the couplingmember is made of a bioresorbable material. In some embodiments, the endmember comprises the externally threaded portion threadably coupledwithin the internally threaded opening of the cap member such that capmember is longitudinally moveable along the end member of the couplingportion. In some such embodiments, the anchor portion comprises a secondengagement end that opposes the first end thereof and engages a firstengagement end of the coupling member. In some such embodiments, each ofthe second engagement end of the anchor portion and the first engagementend of the coupling member include at least one projection and at leastone recess, and the at least one projection of the second engagement endof the anchor portion is positioned within the at least one recess ofthe first engagement end of the coupling member, and the at least oneprojection of the first engagement end of the coupling member ispositioned within the at least one recess of the second engagement endof the anchor portion.

In some embodiments, the coupling member comprises a second engagementend that opposes the first engagement thereof and engages a firstengagement end of the end member. In some such embodiments, each of thesecond engagement end of the coupling member and the first engagementend of the end member include at least one projection and at least onerecess, and the at least one projection of the second engagement end ofthe coupling member is positioned within the at least one recess of thefirst engagement end of the coupling member, and the at least oneprojection of the first engagement end of the coupling member ispositioned within the at least one recess of the second engagement endof the coupling member.

In some embodiments, the end member comprises a torque applicationfeature comprising outer planar surfaces circumferentially arrangedabout the end member. In some embodiments, the anchor portion, thecoupling member and the end member each include a cannulated openingthat are aligned to form a through hole through the implant. In somesuch embodiments, the implant further comprises a tension memberpositioned within the through hole and including a first portion coupledto the end member and a second portion coupled to the anchor member. Insome embodiments, the tension member is elastic. In some embodiments,the tension member comprises a braided suture.

In some embodiments, the second portion of the tension member is coupledto the anchor member via at least one pin. In some such embodiments, theanchor member further comprises at least one transverse openingextending from an exterior surface portion of the anchor member to thecannulated opening thereof, and the at least one pin is positionedwithin the at least one transverse opening and extends into thecannulated opening and in abutment with the second portion of thetension member. In some such embodiments, the at least one pinpositioned within the at least one transverse opening and in abutmentwith the tension member couples the second portion of the tension memberand the anchor portion together. In some such embodiments, the anchormember further comprises at least one slot extending at least partiallythrough the anchor member from an interior surface of the anchor memberthat forms the cannulated opening thereof, the at least one slot beingaligned with the at least one transverse opening such that the at leastone pin positioned within the at least one transverse opening deformsthe second portion of the tension member into the at least one slot tocouple the second portion of the tension member and the anchor portiontogether.

In some embodiments, the first portion of the tension member is coupledto the end member via a pin extending at least partially through the endmember and into the cannulated opening thereof and into abutment withthe first portion of the tension member. In some embodiments, the firstportion of the tension member is coupled to the end member via aninternal crimp ferrule.

In some embodiments, the cap member comprises a shaft portion thatdefines the first end of the cap member and includes the internallythreaded opening, and an enlarged head portion extending from the shaftportion that defines the second end of the cap member and includes anon-circular drive opening extending into the second end. In someembodiments, the anchor portion comprises a shaft portion with a firstend and a second end, a proximal coupling portion extending from thefirst end of the shaft portion of the anchor member to the couplingportion, and a distal portion extending from the second end of the shaftportion of the anchor member. In some such embodiments, at least aportion of the shaft portion of the anchor member comprises the externalthreads. In some such embodiments, the proximal coupling portion is voidof external threads. In some embodiments, the distal portion comprisesat least one surface feature positioned proximate to the first end ofthe anchor portion. In some such embodiments, the at least one surfacefeature comprises at least one cutting flute. In some such embodiments,the at least one surface feature comprises a plurality ofcircumferentially arranged longitudinally extending flutes.

In another aspect of the present disclosure, a method for inserting animplant is provided. The method comprises obtaining the implant. Theimplant comprises a cap member comprising an internally threaded openingextending from a first end thereof, an anchor portion comprising a firstend that defines a tip of the implant and external threads, and acoupling portion coupled to the anchor portion, the coupling portionincluding an externally threaded portion. The method further comprisesengaging the coupling portion with an insertion instrument. The methodalso comprises inserting the coupled coupling portion and anchor memberinto a patient to position the coupling member at least partially in afirst bone and the anchor member in a second bone. The method furthercomprises threadably engaging the externally threaded portion of thecoupling portion within the internally threaded opening of the capmember and longitudinally translating the cap member along the couplingportion toward the anchor portion to such an extent that the cap memberengages the second bone and the implant compresses the first and secondbones together. Longitudinally translating the cap member along thecoupling portion comprises rotating the cap member about the couplingportion.

In some embodiments, the implant comprises an implant as disclosedabove. In some embodiments, the first bone is a fibula and the secondbone is a tibia. In some embodiments, the anchor portion and thecoupling portion are integral during insertion.

In some embodiments, the method further comprises adjusting thelongitudinal position of the cap member after the inserting to adjustthe compression of the first and second bones, the adjusting thelongitudinal position of the cap member comprises further rotating thecap member about the coupling portion such that at least a portion ofthe compression between the first and second bones is released

In some such embodiments, the adjusting the longitudinal position of thecap member comprising releasing at least a portion of the compressionbetween the first and second bones.

In another aspect of the present disclosure, a system is provided. Thesystem comprises an implant comprising an implant as disclosed above,and an insertion instrument for coupling to the implant and rotating theimplant about an axis of the implant.

In some embodiments, the system further comprises a plate with at leastone aperture extending therethrough, and wherein the entirety of theanchor portion, the entirety of the coupling portion and only a portionof the cap member are configured to pass through the at least oneaperture of the implant

These and other objects, features and advantages of this invention willbecome apparent from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention andtogether with the detailed description herein, serve to explain theprinciples of the invention. It is emphasized that, in accordance withthe standard practice in the industry, various features are not drawn toscale. In fact, the dimensions of the various features may bearbitrarily increased or reduced for clarity of discussion. The drawingsare only for purposes of illustrating preferred embodiments and are notto be construed as limiting the invention.

FIG. 1 is a side perspective view of one embodiment of an implant, inaccordance with an aspect of the present disclosure;

FIG. 2 is a side view of the implant of FIG. 1, in accordance with anaspect of the present disclosure;

FIG. 3 is a perspective, cross-sectional view of the implant of FIG. 1taken along line 3-3 in FIG. 2, in accordance with an aspect of thepresent disclosure;

FIG. 4 is an exploded, first end perspective view of the implant of FIG.1, in accordance with an aspect of the present disclosure;

FIG. 5 is an exploded, second end perspective view of the implant ofFIG. 1, in accordance with an aspect of the present disclosure;

FIG. 6 is an exploded, side view of the implant of FIG. 1, in accordancewith an aspect of the present disclosure;

FIG. 7 is a distal, transverse planar view of a fibula and tibia with ak-wire inserted through a plate, the fibula and into the tibia, inaccordance with an aspect of the present disclosure;

FIG. 8 is a distal, transverse planar view of the bones of FIG. 7 with adrill inserted over the k-wire of FIG. 7 through the plate, fibula andinto the tibia, in accordance with an aspect of the present disclosure;

FIG. 9 is a distal, transverse planar view of the bones of FIG. 7 afterthe drill and k-wire are removed, in accordance with an aspect of thepresent disclosure;

FIG. 10 is an anterior view of a portion of a left leg with a portion ofthe implant of FIG. 1 inserted into the bones of FIG. 7, in accordancewith an aspect of the present disclosure;

FIG. 11 is an anterior view of a portion of the left leg of FIG. 10 withthe implant of FIG. 1 inserted into the bones of FIG. 7, in accordancewith an aspect of the present disclosure;

FIG. 12 is a side perspective view of a system including an insertioninstrument and the implant of FIG. 1, in accordance with an aspect ofthe present disclosure;

FIG. 13 is a side perspective view of another implant, in accordancewith an aspect of the present disclosure;

FIG. 14 is a side view of the implant of FIG. 13, in accordance with anaspect of the present disclosure;

FIG. 15 is a first cross-sectional view of the implant of FIG. 13 takenalong line 15-15 in FIG. 14, in accordance with an aspect of the presentdisclosure;

FIG. 16 is a second cross-sectional view of the implant of FIG. 13 takenalong a longitudinal line perpendicular to line 15-15 in FIG. 14, inaccordance with an aspect of the present disclosure;

FIG. 17 is an exploded, first end perspective view of the implant ofFIG. 13, in accordance with an aspect of the present disclosure;

FIG. 18 is an exploded, second end perspective view of the implant ofFIG. 13, in accordance with an aspect of the present disclosure; and

FIG. 19 is an exploded, side view of the implant of FIG. 13, inaccordance with an aspect of the present disclosure.

DETAILED DESCRIPTION FOR CARRYING OUT THE INVENTION

Generally stated, disclosed herein are implants, devices and systemswith a compression cap for achieving ligament fixation. Further, methodsfor using the implants, devices and systems to achieve ligament fixationare discussed.

In this detailed description and the following claims, the wordsproximal, distal, anterior or plantar, posterior or dorsal, medial,lateral, superior and inferior are defined by their standard usage forindicating a particular part or portion of a bone or implant accordingto the relative disposition of the natural bone or directional terms ofreference. For example, “proximal” means the portion of a device orimplant nearest the torso, while “distal” indicates the portion of thedevice or implant farthest from the torso. As for directional terms,“anterior” is a direction towards the front side of the body,“posterior” means a direction towards the back side of the body,“medial” means towards the midline of the body, “lateral” is a directiontowards the sides or away from the midline of the body, “superior” meansa direction above and “inferior” means a direction below another objector structure. Further, specifically in regards to the foot, the term“dorsal” refers to the top of the foot and the term “plantar” refers thebottom of the foot.

Similarly, positions or directions may be used herein with reference toanatomical structures or surfaces. For example, as the current implants,devices, instrumentation and methods are described herein with referenceto use with the bones of the ankle, the bones of the foot, ankle andlower leg may be used to describe the surfaces, positions, directions ororientations of the implants, devices, instrumentation and methods.Further, the implants, devices, instrumentation and methods, and theaspects, components, features and the like thereof, disclosed herein aredescribed with respect to one side of the body for brevity purposes.However, as the human body is relatively symmetrical or mirrored about aline of symmetry (midline), it is hereby expressly contemplated that theimplants, devices, instrumentation and methods, and the aspects,components, features and the like thereof, described and/or illustratedherein may be changed, varied, modified, reconfigured or otherwisealtered for use or association with another side of the body for a sameor similar purpose without departing from the spirit and scope of theinvention. For example, the implants, devices, instrumentation andmethods, and the aspects, components, features and the like thereof,described herein with respect to the left leg may be mirrored so thatthey likewise function with the right leg. Further, the implants,devices, instrumentation and methods, and the aspects, components,features and the like thereof, disclosed herein are described withrespect to the leg for brevity purposes, but it should be understoodthat the implants, devices, instrumentation and methods may be used withother bones of the body having similar structures.

Referring to the drawings, wherein like reference numerals are used toindicate like or analogous components throughout the several views, andwith particular reference to FIGS. 1-6 there is illustrated an implant100 and FIGS. 13-19 there is illustrated an implant 300. The implants100, 300 may be, for example, supportive enough to heal syndesmoticligaments post-operatively. The implants 100, 300 may also, for example,selectively constrain motion in all directions to allow for theligaments to heal. After the syndesmotic ligaments heal, the implants100, 300 allows for physiologic motion. The components of the implants100, 300 may be made of, for example, titanium, stainless steel,polymers, resorbable or time release materials, or another like materialas known by one of ordinary skill in the art. In addition, the implant300 may be made of, for example, polyester or UHMWPE suture, resorbablesuture, co-braids thereof, thermoplastic urethane bumper, and otherresorbable time release materials or polymers. The implant 100, 300 mayalso re-create pressure in the lateral gutter. The surgical methodsinclude drilling a hole through both the fibula and tibia and theninserting an implant 100, 300 to fill the created bone cavities toprovide a stronger post-op construct.

Referring now to FIGS. 1-6 and 10-12, the implant 100 is illustrated. Inaddition to the above, the implant 100 also allows for screw-likeimplantation and temporary rigid fixation, then, after insertion, theimplant 100 is designed to break away at a specific location after aperiod of non-weight bearing. The temporary rigid fixation of theimplant 100 gives the fixed joint time to stabilize through healing andthen allows physiologic motion after the breakaway occurs. The breakawaylocation is set in the space or gap between the fibula and tibia, wherethe subsequent risk of damage to native bone is lower.

With continued reference to FIGS. 1-6 and 10-12, the implant 100includes a proximal end 102 (see FIGS. 3-6), a distal end 104, and abreakaway portion 106 positioned between the proximal end 102 and thedistal end 104. The implant 100 may also include an end member 110, acompression cap 120 removably coupled to the end member 110, and ananchor member 130. The breakaway portion 106 of the implant 100 may bepositioned between the end member 110 and the anchor member 130. The endmember 110 is coupled to the anchor member 130 by the breakaway portion106. The breakaway portion 106 may be recessed into the exterior surfaceof the implant 100 to form a notch, groove, recess, necking or the like,as shown in FIGS. 1-6. The implant 100 may be, for example, a solid,monolithic, or one piece construct, as shown in FIG. 3. It is alsocontemplated that the implant 100 may optionally include, for example, acannulated opening or through hole (not shown) which extends the entirelength of the implant 100.

With continued reference to FIGS. 3-6, the end member or fibula member110 may include a proximal portion 114 and a distal portion 112. Theproximal portion 114 may include, for example, threads from the proximalend 102 and extending toward the distal portion 112. The proximalportion 114 may also include at least one lateral removal member 116.The at least one lateral removal member 116 may be, for example, anexternal hexagonal drive feature, as shown in FIGS. 4-6. The at leastone lateral removal member 116 may include surfaces for engaging anextraction instrument (not shown). The distal portion 112 may be coupledor connected to the breakaway notch 106 on a first side. The distalportion 112 may be, for example, a portion of the shaft member 116 whichis smooth or lacks threads.

The anchor member or tibia member 130 may include a shaft portion orthreaded portion 132, as shown in FIGS. 1-6. The shaft portion 132 mayinclude an insertion end 134 at the second or distal end 104 of theimplant 100 and the shaft portion 132. As shown in FIGS. 1-6, the anchormember 130 may also include a distal feature or portion 136 positionedat the insertion end 134 of the anchor member 130. The distal portion136 may include surfaces for engaging an extraction instrument (notshown). The surfaces of the distal portion 136 may be, for example,cutting flutes or teeth, as shown in FIGS. 1-6. Alternatively, thesurfaces of the distal portion 136 may form, for example, a hexagonaldrive portion. The insertion end 134 of the anchor member 130 may alsoinclude, for example, an opening or recess 138 extending into the coreof the anchor member 130 along at least a portion of the longitudinalaxis of the implant 100, as shown in FIG. 3. In an embodiment of theanchor member 130 including a cannulation (not shown), the opening 138may be, for example, continuous or aligned with the cannulation.

The shaft portion 132 may also include a proximal coupling portion 140at a first end of the shaft portion 132 opposite the insertion end 134.The proximal coupling portion 140 is connected to the breakaway portion106 on a second side opposite the distal portion 112 of the end member110. The proximal coupling portion 140 may be, for example, a section ofthe shaft portion 132 which lacks threads and includes at least onelateral removal member 142. The at least one lateral removal member 142may be, for example, an external hexagonal drive feature, as shown inFIGS. 1-6.

As shown in FIGS. 1-6, the breakaway portion 106 may be, for example, anotch, groove, necking, or recess into the exterior surface of theimplant 100. The notch, groove, necking, or recess may have, forexample, a curved, rounded, or “V” shape. Alternatively, the breakawayportion 106 may be, for example, a resorbable material or memberpositioned between and coupling the end member 110 to the anchor member130. The resorbable breakaway portion 106 may include, for example, anotch, groove, necking, or recess with a curved, rounded or “V” shapeor, alternatively, the resorbable breakaway portion 106 may be flushwith the exterior surface of the distal portion 112 and proximalcoupling portion 140. The breakaway portion 106 may initially provide aconnection between the end member 110 and anchor member 130 to constrainmotion between the bones 210, 220, as shown in FIGS. 10 and 11. Then,once the breakaway portion 106 breaks or resorbs into the patient, theend member 110 and anchor member 130 will be separated and motionbetween the bones 210, 220 will no longer be constrained. When theimplant 100 with the breakaway portion 106 breaks, the proximal end ofthe anchor member 130 may be, for example, smooth or flat. The implant100 may have, for example, a breakaway feature ratio between breakawaynotch 106 and the distal portion 112 of, for example, 64% to 89% andmore preferably, 75% to 82%.

Although not shown it is also contemplated that the breakaway portion106 may include, for example, an internal drive feature (not shown) forreceiving an extraction instrument to remove the anchor member 130. Theinternal drive feature (not shown) may be, for example, a hexagonal orother multi-lobed drive opening. In addition, it is also contemplatedthat the breakaway portion 106 may also include, for example, at leastone hole (not shown). The at least one hole (not shown) may be, forexample, at least one through hole extending through the entire diameterof the implant 100 perpendicular to the longitudinal axis oralternatively, only through a portion of the implant 100. The holes (notshown) may be radially positioned, for example, between the distalportion 112 of the end member 110 and the proximal coupling portion 140of the anchor member 130. In an embodiment, the breakaway portion 106may include, for example, at least one channel (not shown) extendinginto the implant 100 from an exterior surface to form at least one blindhole, pocket or opening (not shown). In addition, the breakaway portion106 may include an opening (not shown) positioned, for example, in thecenter of the anchor member 130 and extending into the anchor member 130along the longitudinal axis of the implant 100. The breakaway portion106 is designed or configured to fail at the precise location of thebreakaway portion 106. Specifically, the materials and sizes of theimplant 100 are selected to withstand a desired torsional force, bendingmoment, etc. at the breakaway portion 106. Alternative external andinternal removal features that allow for engagement of an extractioninstrument to remove the anchor member 130 from a lateral side of thepatient are also contemplated.

With continued reference to FIGS. 1-6 and 10-12, the compression cap,fibula cap, cap 120 may include, for example, a head or button portion122 at a first or proximal end and a shaft portion 126 extending awayfrom an underside of the head portion 122. The head portion 122 may alsoinclude a tool engagement opening 124 positioned on a surface that isopposite the shaft portion 126, as shown in FIGS. 1, 3 and 4. The toolengagement opening 124 may have a multi-lobed shape, although otherpolygonal shapes are also contemplated, including a hexagonal shape or ahexalobular drive feature, for receiving an insertion tool. The cap 120may also include an opening 128 extending into the shaft portion 126from a second or distal end towards the head portion 122. The opening128 may be, for example, threaded along at least a portion of theinterior surface of the opening 128, as shown in FIG. 3. The threadedopening 128 may include threads that correspond to the threads on thethreaded portion 114 of the fibula member 110, as shown in FIG. 3. Thecap 120 may have, for example, a left-handed threaded attachment. Thecap 120 may be, for example, moveable and may be actuated to compressthe bones 210, 220 together. With continued reference to FIG. 3, thetool engagement opening 124 may be separated from the opening 128.Alternatively, it is also contemplated that the tool engagement opening124 could, for example, extend to engage the opening 128 forming athrough hole (not shown) within the cap 120. The through hole (notshown) may be, for example, configured to receive a guide pin, k-wire,or the like.

The implant 100 may have a length of, for example, approximately 40 mmto 70 mm. In an embodiment, the total length of the coupled end member110 and cap 120 may remain constant and the length of the anchor member130 may be variable to correspond to the varying size of a patient'sbones 210, 220. Alternatively, in another embodiment, the coupled endmember 110 and cap 120 may, for example, be available in multiplelengths to correspond to the varying size of a patient's bones 210, 220and the length of the anchor member 130 may remain constant. In yetanother embodiment, both the total length of the coupled end member 110and cap 120 and the length of the anchor member 130 may be available inmultiple lengths to allow for selection based on the size of thepatient's bones 210, 220. The assembled end member 110 and cap 120 mayhave a length of, for example, between approximately 10 mm and 20 mm.The anchor member 130 may have a length of, for example, betweenapproximately 20 mm and 60 mm.

Referring now to FIGS. 7-11, a method of inserting the implant 100 isshown. The method may optionally include positioning a plate 200 orwasher (not shown) on a bone 220, for example, a fibula. The plate 200or washer (not shown) may provide a buttress means for engaging the cap120. The method may also include driving a k-wire or guide wire 202through two bones 210, 220, for example, a fibula 220 and tibia 210, asshown in FIG. 7. If a plate 200 is used, the k-wire 202 may be insertedthrough an opening in the plate 200. Next, a drill bit 204 may beinserted over the k-wire 202 by aligning a cannulated opening 206 in thedrill bit 204 with the k-wire 202, as shown in FIG. 8. The drill bit 204may be used to drill openings 212, 222 through the bones 210, 220, asshown in FIG. 9. The openings 212, 222 may have a diameter, for example,that corresponds to the minor diameter or shaft of the anchor member130. The openings 212, 222 may form an opening 208 for receiving theimplant 100. After the opening 208 is drilled, the drill bit 204 andk-wire 202 may be removed from the bones 210, 220, as shown in FIG. 9.Optionally, after removing the drill bit 204 and prior to removing thek-wire 202, measurements of the opening 208 may be taken using acannulated depth gauge (not shown) inserted over the k-wire 202. Oncethe measurements are taken, the k-wire 202 may then be removed.Alternatively, the k-wire 202 may be removed from the bones 210, 220 anda standard depth gauge (not shown) may be used to take the measurements.For example, an overall or first measurement of the opening or drillhole 208, such as a measurement to the far cortex of the tibia, may betaken using a cannulated depth gauge, standard depth gauge or other likeinstrument. The surgeon may also take a second measurement of theportion of the opening 208 in the fibula using, for example, a standarddepth gauge or like instrument, to determine the size of the assembledend member 110 and cap 120. Then, a driver instrument (not shown) may beused to insert the coupled end member 110 and tibia member 130 of theimplant 100 into the opening 208 in the bones 210, 220, as shown in FIG.11. The implant 100 may be inserted to position the anchor member 130 inthe tibia 210, the end member 110 in the fibula 220, and the breakawaynotch 106 in a tibiofibular space or gap between the tibia 210 andfibula 220, as shown in FIG. 10. The space or gap may be, for example,approximately 3 mm. The torsional force applied to the end member 110for inserting the implant 100 may be transmitted to the anchor member130 through the breakaway portion 106. Next, the driver instrument (notshown) may be removed from the end member 110 of the implant 100 and acap 120 may be inserted onto the end member 110. An insertion instrument250, such as shown in FIG. 12, may be used to screw the cap 120 onto thethreaded portion 114 of the end member 110. As the cap 120 is coupled tothe end member 110, the head portion 122 contacts the fibula 220 or boneplate 200 and acts to compress the tibia 210 and fibula 220 with theinserted anchor member 130. Once the desired clear space or gap betweenthe tibia 210 and fibula 220 and/or gutter pressure is achieved, theinsertion instrument 250 may be removed from the tool engagement opening124 in the cap 120 and the surgical procedure may be completed. Duringinsertion of the cap 120, the torque may be, for example, measured orlimited to facilitate a desired compression range between the bones 210,220.

After inserting the implant 100, the cap 120 may be, for example,optionally adjusted to release some of the compression between the bones210, 220 based on patient or doctor preference and/or surgical goal.Also, after inserting the implant 100, the breakaway portion 106 mayeventually fail or fracture leaving the end member 110 separated fromthe anchor member 130 and the motion between the tibia 210 and fibula220 no longer constrained. Once the breakaway portion 106 fails, thepatient's physiologic motion is restored. Absent any furthercomplications, the end member 110 and anchor member 130 may remain inthe patient's fibula 220 and tibia 210, respectively. However, ifhardware removal is required, the end member 110 may be removed from thefibula 220 after the breakaway portion 106 fractures. In addition, ifnecessary, the anchor member 130 may be removed from the tibia 210, aswell. The anchor member 130 may be removed, for example, medially usingthe distal feature 136 or laterally using the at least one lateralremoval member 142 of the proximal coupling portion 140.

A system including an insertion instrument 250 and implant 100 is shownin FIG. 12. The insertion instrument 250 includes a handle portion 252and a driver bit 260 extending away from the handle portion 252. Thehandle portion 252 may include a handle 254 at a first end and acoupling portion 256 at a second end. The first end of the couplingportion 256 is attached to a proximal end of the handle 254. Thecoupling portion 256 may include an opening 258 extending into thecoupling portion 256 from a second end. The opening 258 may beconfigured or sized and shaped to receive the driver bit 260. The driverbit 260 may include a first portion 262 at a first end and a secondportion 264 at a second end. The first portion 262 may be separated fromthe second portion 264 by a groove 266. The driver bit 260 may alsoinclude a securement or engagement feature 268 at the first end and adriver member or feature 270 at a second end. The second portion 264 maybe inserted into the opening 258 of the coupling portion 256. When thedriver bit 260 is inserted into the handle portion 252, the engagementfeature 268 of the driver bit 260 may contact a bottom of the opening258 and engage a corresponding securement feature (not shown) within theopening 258 of the handle portion 252. The driver feature 270 may besized and shaped or configured to engage the tool engagement opening 124of the cap member 120 to insert the cap member 120 onto the proximalportion 114 of the end member 110. The driver feature 270 may have, forexample, a multi-lobed shape or other polygonal shape, including ahexagonal shape or a hexalobular drive feature.

Referring now to FIGS. 13-19, another implant 300 is shown. In additionto the above, the implant 300 also allows for screw-like implantationand temporary rigid fixation, then, after insertion, the implant 300transitions to semi-constrained motion. The temporary rigid fixation ofthe implant 300 gives the fixed joint time to stabilize through healingand then over time allows physiologic motion to be restored. The area ofallowed motion in implant 300 is in the space or gap between the fibulaand tibia, where the subsequent risk of damage to bone is lower. Thetension member or tether 350 mimics the interosseous ligament in bothlocation and orientation. In addition, the components in the tibia andfibula protect the bone from abrasion from the tension member 350, andvice versa.

The implant 300 includes a proximal end 302, a distal end 304, and acoupling member 360 positioned between the proximal end 302 and thedistal end 304. The implant 300 may also include a fibula member or endmember 310, an anchor member or tibia member 330, a coupling member 360positioned between and engaging the end member 310 and the anchor member330, and a tension member 350 positioned within a cannulated openingthat extends through the end member 310, anchor member 330 and thecoupling member 360. The implant 300 may also include a compression cap120 removably coupled to the end member 310. The compression cap 120 maybe of the type described above with reference to implant 100 and whichwill not be described again here for brevity sake. The coupling member360 may be positioned between the end member 310 and the anchor member330 and allow for the anchor member 330 to be secured into the bones210, 220 when the end member 310 is rotated. The tension member 350 mayextend through a center of at least a portion of the aligned end member310, the coupling member 360, and at least a portion of the anchormember 330.

The implant 300 may have a length of, for example, approximately 40 mmto 70 mm. In one embodiment, the length of the coupled end member 310and coupling member 360 may remain constant, while the length of theanchor member 330 may be variable to correspond to the varying size of apatient's bones 210, 220. Alternatively, in another embodiment, the endmember 310 and coupled cap 120 may, for example, be available inmultiple lengths to correspond to the varying sizes of patient's bones210, 220 and the lengths of the anchor member 330 and the couplingmember 360 may remain constant. In yet another embodiment, both thecoupled end member 310 and cap 120, as well as the anchor member 330 maybe available in multiple lengths to allow for selection based on thesize of the patient's bones 210, 220 and the coupling member 360 mayremain constant. Therefore, the coupled end member 310 and cap 120 mayhave a length of, for example, between approximately 10 mm and 20 mm,the anchor member 330 may have a length of, for example, betweenapproximately 20 mm and 60 mm, and the coupling member 360 may have alength of, for example, approximately 3 mm.

As shown in FIGS. 13-19, the end member 310 may include a proximalportion 312 and a distal portion or engagement end 316. The proximalportion 312 may include, for example, threads from the proximal end 302and extending toward the distal portion 316. The proximal portion 312may also include at least one lateral removal member 314. The at leastone lateral removal member 314 may be, for example, an externalhexagonal drive feature, as shown in FIGS. 17-19. The at least onelateral removal member 314 may include surfaces for engaging anextraction instrument (not shown). The end member 310 may also include athrough hole or cannulated opening 324. The cannulated opening 324 mayextend through the entire end member 310 along the longitudinal axis ofthe end member 310.

The distal portion, engagement end or mating jaw 316 may include atleast one protrusion or tooth 318 and at least one groove or recess 320,as shown in FIGS. 13-19. For example, the engagement end 316 may includethree protrusions 318 alternating with three recesses 320. The endmember 310 may also include an engagement surface 322 positioned betweenthe at least one protrusion 318 for receiving a first end of thecoupling member 360. In addition, the end member 310 may include aninternal crimping feature 326, for example, a crimp ferrule positionedwithin the through hole 324 near the first end 302, as shown in FIGS. 15and 16. The crimping feature 326 may secure a first end 352 of thetension member 350 to the end member 310. Alternatively, the end member310 may include at least one transverse opening (not shown) in a firstside of the proximal portion 312 and at least one slot, window, recess,aperture (not shown) inset into the interior diameter of the opening 324and positioned opposite the at least one transverse opening (not shown).The at least one transverse opening (not shown) may be sized and shapedto receive a pin or engagement member (not shown). At least one pin (notshown) may be inserted through the at least one transverse opening (notshown) to engage the tension member 350 and push a portion of thetension member 350 into the opposing slots (not shown) securing thetension member 350 to the end member 310. The at least one slot (notshown) may be, for example, slightly offset from the at least onetransverse opening (not shown) to provide additional securement of thetension member 350 to the end member 310. The pins (not shown) may alsobe coupled to the end member 310 by, for example, laser welding toprevent a pin from disengaging the end member 310 after insertion into apatient. The end member 310 may be made of, for example, titanium,stainless steel, polymer, or another like material as would be known byone of ordinary skill in the art.

With continued reference to FIGS. 13-19, the anchor member 330 mayinclude a shaft portion or threaded shaft 332 with a through hole orcannulated opening 334 extending through the shaft portion 332 from afirst end to a second end along the longitudinal axis of the anchormember 330. The anchor member 330 may also include an engagement end ormating jaw 340 at the first end and an insertion end 336 at the secondend. The insertion end 336 may include at least one cutting element 338,for example, at least one cutting flute, as shown in at least FIGS.13-19. The at least one cutting element 338 may be, for example, threecutting flutes. It is also contemplated that the cutting flutes at theinsertion end 336 may be used as a removal feature if a medial approachis used to remove the anchor member 330. The shaft portion 332 may be,for example, threaded along the entire length of the shaft or only alonga portion of the shaft. The engagement end or mating jaw 340 may includeat least one protrusion or tooth 342 and at least one groove or recess344, as shown in FIGS. 17-19. For example, the engagement end 340 mayinclude three protrusions 342 alternating with three recesses 344.

The shaft portion 332 may also include at least one transverse opening346 extending from an exterior surface of the shaft portion 332 into thethrough hole 334. The anchor member 330 may also include at least oneslot, window, recess, or aperture 348 inset into the interior diameterof the through hole 334 or extending from an exterior surface of theshaft portion 332 into the through hole 334. The at least one slot 348may be positioned, for example, opposite the at least one transverseopening 346. The at least one transverse opening 346 may be sized andshaped to receive at least one pin or engagement member 358. As shown inFIGS. 15 and 16, the pin 358 may be inserted through the at least onetransverse opening 346 to engage the tension member 350 and push aportion 356 of the tension member 350 into the opposing at least oneslot 348 securing the tension member 350 to the anchor member 330, asshown in FIGS. 15 and 16. Although not shown, the slots 348 may be, forexample, slightly offset from the openings 346 to provide additionalsecurement of the tension member 350 to the anchor member 330. The pins358 may also be coupled to the anchor member 330 by, for example, laserwelding to prevent a pin 358 from disengaging the anchor member 330after insertion into a patient. The anchor member 330 may be made of,for example, titanium, stainless steel, polymer, and like materials asknown by one of ordinary skill in the art.

Referring now to FIGS. 15-19, the tension member 350 may include a firstend 352 and a second end 354. The first end 352 may be, for example,positioned within the cannulated opening 324 of the end member 310. Thefirst end 352 may be secured to the end member 310 by, for example, aninternal crimp ferrule 326 or, alternatively, pins (not shown) insertedthrough the at least one opening (not shown) to engage the tensionmember 350 and optionally an opposing slot (not shown), as described ingreater detail above with respect to the openings 346 and slots 348 ofthe anchor member 330. The second end 354 may, for example, extendthrough a portion of the anchor member 330. The second end 354 may besecured to the anchor member 330 by, for example, at least one pin 358inserted through the at least one opening 346 to engage the tensionmember 350 and at least one opposing slot 348, as shown in FIGS. 15 and16 and described in greater detail above. The tension member 350 may be,for example, a braided suture, such as a size #5-#9 braided suture. Thetension member 350 may be, for example, a single cross-section strand ofsuture or multiple loops.

As shown in FIGS. 13-19, the coupling member 360 may include a throughhole or cannulated opening 362 extending through the coupling member 360along a longitudinal axis of the coupling member 360. The couplingmember 360 may also include a first engagement end or first mating jaw364 at a first end and a second engagement end or second mating jaw 370at a second end. The first engagement end 364 may include at least oneprotrusion or tooth 366 and at least one groove or recess 368, as shownin FIG. 17-19. For example, the first engagement end 364 may includethree protrusions 366 alternating with three recesses 368. The secondengagement end 370 may include at least one protrusion or tooth 372 andat least one groove or recess 374, as shown in FIGS. 17-19. For example,the second engagement end 370 may include three protrusions 372alternating with three recesses 374. The protrusions 372 may be spaced,for example, 3 mm apart. The coupling member 360 may be made of, forexample, a bioresorbable material, such as, PLLA, PGA, PLDA, PL-DLA,copolymers of each, resorbable calcium composites, and like materials asknown by one of ordinary skill in the art.

As shown in FIGS. 13-16, the anchor member 330 is linked dynamically tothe end member 310 by the tension member 350 and the coupling member360. The implant 300 may be assembled by inserting the engagement end316 of the end member 310 into the first engagement end 364 of thecoupling member 360 and inserting the engagement end 340 of the anchormember 330 into the second engagement end 370 of the coupling member360. The coupling member 360 will be positioned between the end member310 and the anchor member 330. With the cannulated openings 324, 334,362 of the end member 310, anchor member 330 and coupling member 360,respectively, aligned. Then, the tension member 350 may be inserted intothe cannulated openings 324, 334, 362. The tension member 350 may besecured to the end member 310 by securing or tightening the crimpferrule 326 around the tension member 350 and/or inserting at least onepin (not shown) through at least one transverse opening (not shown) inthe end member 310 to engage and secure the tension member 350. Thetension member 350 may also be secured to the anchor member 330 byinserting pins 358 through the at least one opening 346 in the anchormember 330 to engage and secure the tension member 350 or alternatively,by securing or tightening crimp members (not shown) around the tensionmember 350 at the second end. The assembled end member 310, couplingmember 360, and anchor member 330 may be coupled together as shown inFIGS. 13-16 during insertion into a patient. After the tension member350 is secured to the end member 310 and anchor member 330, the cap 120may be coupled to the end member 310. For example, the threads of theopening 128 may engage the threads of the proximal portion 312 of theend member 310 to tighten the cap 120 onto the end member 310. The cap120 may overlap the end member 310 a distance that corresponds with theamount of compression needed to create the desired space or gap orlateral gutter pressure between the bones 210, 220.

A method of inserting the implant 300 may optionally include positioninga plate 200 or washer (not shown) on a bone 220, for example, a fibula.The plate 200 or washer (not shown) may provide a buttress means forengaging the cap 120. The method may also include driving a k-wire orguide wire 202 through two bones 210, 220, for example, a fibula 220 andtibia 210, as shown in FIG. 7. Next, as shown in FIG. 8, a drill bit 204of an instrument (not shown) may be inserted over the k-wire 202 byaligning a cannulated opening 206 in the drill bit 204 with the k-wire202. The drill bit 204 may be used to drill an opening 208 through thebones 210, 220. The opening 208 may include, for example, an opening 212in the tibia 210 and an opening 222 in the fibula 220. The opening 208may also have a diameter, for example, that corresponds to the minordiameter of the anchor member 330. After the opening 208 is drilled, thedrill bit 204 and optionally the k-wire 202 may be removed from thebones 210, 220, as shown in FIG. 9. Optionally, after removing the drillbit 204 from the bones 210, 220 and prior to removing the k-wire 202,measurements of the depth of the opening 208 may be taken using acannulated depth gauge (not shown) inserted over the k-wire 202. Oncethe measurements are taken, the k-wire 202 may then be removed.Alternatively, the k-wire 202 may be removed from the bones 210, 220 anda standard depth gauge (not shown) may be used to take the measurements.For example, an overall or first depth measurement of the opening ordrill hole 208, such as a measurement to the far cortex of the tibia,may be taken using a cannulated depth gauge, standard depth gauge orother like instrument. The surgeon may also take a second depthmeasurement of the portion of the opening 208 in the fibula using, forexample, a standard depth gauge or like instrument, to determine thesize of the end member 310 and cap 120. Then, an instrument, forexample, insertion instrument 250 as shown in FIG. 12, may be used toinsert the coupled end member 310, coupling member 360, anchor member330 and tension member 350 of the implant 300 into the opening 208 inthe bones 210, 220. The implant 300 may be inserted to position theanchor member 330 in the tibia 210, the end member 310 in the fibula220, and the coupling member 360 in a tibiofibular space or gap. Thetorsional force applied to the end member 310 for inserting the implant300 may be transmitted to the anchor member 330 through the couplingmember 360. Next, the instrument may be removed from end member 310 ofthe implant 300. A cap 120 may then be aligned with and secured onto theend member 310 by engaging the threads of the opening 128 with thethreads of the proximal portion 312 of the end member 310. As the cap120 is tightened or loosened, the clear space between the bones 210, 220is correspondingly adjusted to reduce or increase the space or gapbetween the bones 210, 220 and/or gutter pressure, while the couplingmember 360 remains positioned in the space or gap. During insertion ofthe cap 120, the torque may be, for example, measured or limited tofacilitate a desired compression range between the bones 210, 220.Finally, the surgical procedure may be completed.

After inserting the implant 300, the cap 120 may be, for example,optionally adjusted to release some of the compression between the bones210, 220 based on a patient or doctor preference and/or surgical goals.Also after inserting the implant 300, the coupling member 360 willeventually fail leaving the end member 310 coupled to the anchor member330 only by the tension member 350. The coupling member 360 may fail,for example, after at least a portion of the coupling member 360 isresorbed into the patient. Failure of the coupling member 360 will allowfor semi-constrained motion between the tibia 210 and fibula 220 via thetension member 350. The flexibility of the tension member 350 may allowfor diastatic motion of the implant 300. Thus, the implant 300 allowsfor the patient's physiologic motion to be restored in ananterior-posterior direction, a superior-inferior direction, as well asallowing for fibular rotation, at the joint based on the strength of thetension member 350 and the resorbable coupling 360.

As may be recognized by those of ordinary skill in the art based on theteachings herein, numerous changes and modifications may be made to theabove-described and other embodiments of the present invention withoutdeparting from the scope of the invention. The end member, anchormember, breakaway portion, coupling member, tension member, cap andother components of the implant and/or system as disclosed in thespecification, including the accompanying abstract and drawings, may bereplaced by alternative component(s) or feature(s), such as thosedisclosed in another embodiment, which serve the same, equivalent orsimilar purpose as known by those skilled in the art to achieve thesame, equivalent or similar results by such alternative component(s) orfeature(s) to provide a similar function for the intended purpose. Inaddition, the implants and systems may include more or fewer componentsor features than the embodiments as described and illustrated herein.For example, the components and features of FIGS. 1-12 and FIGS. 13-19may all be used interchangeably and in alternative combinations as wouldbe modified or altered by one of skill in the art. Accordingly, thisdetailed description of the currently-preferred embodiments is to betaken in an illustrative, as opposed to limiting of the invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprise” (andany form of comprise, such as “comprises” and “comprising”), “have” (andany form of have, such as “has”, and “having”), “include” (and any formof include, such as “includes” and “including”), and “contain” (and anyform of contain, such as “contains” and “containing”) are open-endedlinking verbs. As a result, a method or device that “comprises,” “has,”“includes,” or “contains” one or more steps or elements possesses thoseone or more steps or elements, but is not limited to possessing onlythose one or more steps or elements. Likewise, a step of a method or anelement of a device that “comprises,” “has,” “includes,” or “contains”one or more features possesses those one or more features, but is notlimited to possessing only those one or more features. Furthermore, adevice or structure that is configured in a certain way is configured inat least that way, but may also be configured in ways that are notlisted.

The invention has been described with reference to the preferredembodiments. It will be understood that the architectural andoperational embodiments described herein are exemplary of a plurality ofpossible arrangements to provide the same general features,characteristics, and general system operation. Modifications andalterations will occur to others upon a reading and understanding of thepreceding detailed description. It is intended that the invention beconstrued as including all such modifications and alterations.

What is claimed is:
 1. An implant, comprising: a cap member comprisingan internally threaded opening extending from a first end thereof; ananchor portion comprising external threads and a first end that definesa tip of the implant; and a coupling portion extending between the capmember and the anchor portion, the coupling portion including anexternally threaded portion threadably coupled within the internallythreaded opening of the cap member, wherein the cap member islongitudinally moveable along the coupling portion; wherein the couplingportion comprises a breakaway portion with a circumferential groove;wherein the coupling portion comprises outer planar surfacescircumferentially arranged about the coupling portion.
 2. The implant ofclaim 1, wherein the cap member comprises: a shaft portion that definesthe first end of the cap member and includes the internally threadedopening; and an enlarged head portion extending from the shaft portionthat defines a second end of the cap member, the second end of the capmember defining a free end of the implant that opposes the tip of theimplant.
 3. The implant of claim 2, wherein the cap member furthercomprises a noncircular drive opening extending from the second endthereof.
 4. The implant of claim 1, wherein the anchor portioncomprises: a shaft portion with a first end portion, a second endportion and external threads; a proximal coupling portion extending fromthe first end portion of the shaft portion of the anchor member to thecoupling portion; and a distal portion extending from the second endportion of the shaft portion of the anchor member and defining the firstend of the anchor portion.
 5. The implant of claim 4, wherein the distalportion comprises a plurality of circumferentially arrangedlongitudinally extending flutes positioned proximate to the first end ofthe anchor portion.
 6. The implant of claim 4, wherein the couplingportion comprises: a coupling member coupled to the anchor portion; andan end member coupled to the coupling member, wherein the couplingmember and the end member are separate and distinct components.
 7. Theimplant of claim 6, wherein the coupling member is made of abioresorbable material.
 8. The implant of claim 6, wherein the endmember comprises the externally threaded portion threaded portionthreadably coupled within the internally threaded opening of the capmember, wherein the cap member is longitudinally moveable along the endmember of the coupling portion.
 9. The implant of claim 6, wherein theanchor portion comprises a second engagement end that opposes the firstend thereof and engages a first engagement end of the coupling member,wherein each of the second engagement end of the anchor portion and thefirst engagement end of the coupling member include at least oneprojection and at least one recess, and wherein the at least oneprojection of the second engagement end of the anchor portion ispositioned within the at least one recess of the first engagement end ofthe coupling member, and the at least one projection of the firstengagement end of the coupling member is positioned within the at leastone recess of the second engagement end of the anchor portion.
 10. Theimplant of claim 9, wherein the coupling member comprises a secondengagement end the opposes the first engagement end thereof and engagesa first engagement end of the end member, wherein each of the secondengagement end of the coupling member and the first engagement end ofthe end member include at least one projection and at least one recess,and wherein the at least one projection of the second engagement end ofthe coupling member is positioned within the at least one recess of thefirst engagement end of the coupling member is positioned within the atleast one recess of the second engagement end of the coupling member.11. The implant of claim 6, wherein the end member comprises a torqueapplication feature comprising outer planar surfaces circumferentiallyarranged about the end member.
 12. The implant of claim 6, wherein theanchor portion, the coupling member and the end member each include acannulated opening that are aligned to form a through hole, and whereinthe implant further comprises a tension member positioned within thethrough hole and including a first portion coupled to the end member anda second portion coupled to the anchor member.
 13. The implant of claim12, wherein the tension member comprises an elastic suture.
 14. Theimplant of claim 12, wherein the anchor member further comprises atleast one transverse opening extending from an exterior surface portionof the anchor member to the cannulated opening thereof, and at least onepin positioned within the at least one transverse opening and extendinginto the cannulated opening and in abutment with the second portion ofthe tension member to couple the second portion of the tension memberand the anchor portion together.
 15. The implant of claim 14, whereinthe anchor further comprises at least one slot extending at leastpartially through the anchor member from an interior surface of theanchor member that forms the cannulated opening thereof, the at leastone slot being aligned with the at least one transverse opening suchthat the at least one pin positioned within the at least one transverseopening deforms the second portion of the tension member into the atleast one slot to couple the second portion of the tension member andthe anchor portion together.
 16. A system, comprising: an implant,comprising: a cap member comprising an internally threaded openingextending from a first end thereof; an anchor portion comprisingexternal threads and a first end that defines a tip of the implant; anda coupling portion extending between the cap member and the anchorportion, the coupling portion including an externally threaded portionthreadably coupled within the internally threaded opening of the capmember, wherein the cap member is longitudinally moveable along thecoupling portion; wherein the coupling portion comprises a breakawayportion with a circumferential groove; wherein the coupling portioncomprises outer planar surfaces circumferentially arranged about thecoupling portion; an insertion instrument for coupling to the implantand rotating the implant about an axis of the implant; and a plate withat least one aperture extending therethrough, wherein the entirety ofthe anchor portion, the entirety of the coupling portion and only aportion of the cap member are configured to pass through the at leastone aperture of the implant.
 17. An implant, comprising: a cap membercomprising an internally threaded opening extending from a first endthereof, an anchor portion comprising external threads and a first endthat defines a tip of the implant; and a coupling portion extendingbetween the cap member and the anchor portion, the coupling portionincluding an externally threaded portion threadably coupled within theinternally threaded opening of the cap member, wherein the cap member islongitudinally moveable along the coupling portion; a shaft portion witha first end portion, a second end portion and external threads; aproximal coupling portion extending from the first end portion of theshaft portion of the anchor member to the coupling portion; a distalportion extending from the second end portion of the shaft portion ofthe anchor member and defining the first end of the anchor portion;wherein the coupling portion comprises: a coupling member coupled to theanchor portion; and an end member coupled to the coupling member,wherein the coupling member and the end member are separate and distinctcomponents; wherein the anchor portion comprises a second engagement endthat opposes the first end thereof and engages a first engagement end ofthe coupling member, wherein each of the second engagement end of theanchor portion and the first engagement end of the coupling memberinclude at least one projection and at least one recess, and wherein theat least one projection of the second engagement end of the anchorportion is positioned within the at least one recess of the firstengagement end of the coupling member, and the at least one projectionof the first engagement end of the coupling member is positioned withinthe at least one recess of the second engagement end of the anchorportion.
 18. A system, comprising: an implant, comprising: a cap membercomprising an internally threaded opening extending from a first endthereof; an anchor portion comprising external threads and a first endthat defines a tip of the implant; and a coupling portion extendingbetween the cap member and the anchor portion, the coupling portionincluding an externally threaded portion threadably coupled within theinternally threaded opening of the cap member, wherein the cap member islongitudinally moveable along the coupling portion; a shaft portion witha first end portion, a second end portion and external threads; aproximal coupling portion extending from the first end portion of theshaft portion of the anchor member to the coupling portion; a distalportion extending from the second end portion of the shaft portion ofthe anchor member and defining the first end of the anchor portion;wherein the coupling portion comprises: a coupling member coupled to theanchor portion; and an end member coupled to the coupling member,wherein the coupling member and the end member are separate and distinctcomponents; wherein the anchor portion comprises a second engagement endthat opposes the first end thereof and engages a first engagement end ofthe coupling member, wherein each of the second engagement end of theanchor portion and the first engagement end of the coupling memberinclude at least one projection and at least one recess, and wherein theat least one projection of the second engagement end of the anchorportion is positioned within the at least one recess of the firstengagement end of the coupling member, and the at least one projectionof the first engagement end of the coupling member is positioned withinthe at least one recess of the second engagement end of the anchorportion; an insertion instrument for coupling to the implant androtating the implant about an axis of the implant; and a plate with atleast one aperture extending therethrough, wherein the entirety of theanchor portion, the entirety of the coupling portion and only a portionof the cap member are configured to pass through the at least oneaperture of the implant.